Many workplaces contain spaces that are considered “confined” because of their configurations. A confined space is large enough and configured in such a way that you can enter and perform assigned work. A confined space has a limited or restricted means of entrance or exit, and a configuration that can make first aid, rescue, evacuation, or other emergency response activities difficult. They are not designed or intended for continuous occupancy.

Examples include storage tanks or bins, mixing tanks, railroad tank cars, silos, vaults, and pits. Think of any large tank used for holding liquid. Confined spaces create the ideal conditions for the onset of claustrophobia. Confined spaces can be large or small and above or below ground.

There are two types of confined spaces, non-permit required and permit required.

Permit required confined spaces are identified by one or more of the following:

• A hazardous atmosphere
• A hazardous internal configuration
• An entrapment hazard
• Other physical, chemical, mechanical, or biological hazards.

Your employer must conduct hazard assessments to determine present or potential hazards in a confined workspace. If the hazards cannot be eliminated but can be controlled, then the confined space is classified as a permit-required confined space. This means that entry into the space requires a special permit and training, and that workers must follow certain policies and procedures.

If all physical and atmospheric hazards in a confined space can be eliminated and not just controlled, the confined space is classified as a non-permit confined space. Entry into a non-permit confined space does not require a permit and can occur as many times as necessary. However, due to the limited space, workers should still follow safety precautions.

A permit-required confined space can be reclassified as a non-permit confined space only for as long as the hazards remain eliminated. If a hazard cannot be eliminated, the only remaining option for entry is the enactment of a Permit-Required Confined Space Program in order to control the hazard.

Your company’s Permit-required Confined Space Entry Program is its overall policy and plan for protecting you and other employees and contractors against confined space hazards, and for regulating entry into its permit-required spaces. Before you may enter a permit space, your supervisor and/or the attendant must take any measures necessary to isolate the permit space and eliminate or control hazards. These measures include lockout or tagging of equipment to ensure that it does not present a hazard.

Measures also include testing and monitoring the air for contaminants and adequate oxygen, as well as purging, ventilating, and flushing unsafe atmospheres or chemicals from the space. If a permit space requires forced air ventilation, the ventilator must eliminate or reduce hazardous atmospheric conditions to within acceptable limits, employing PPE as necessary to accomplish this, and maintain a safe atmosphere until the work is completed and personnel have left the space. Before you may enter a permit space, your supervisor and/or the attendant must test the internal atmosphere of the space with calibrated, direct-reading instruments.

Before anyone may enter the space, an authorized supervisor must also review and sign an entry permit that specifies the purpose and duration, the names of the entry team members, hazards and controls specific to the confined space, PPE and equipment, the supervisor’s signature and rescue resources.

Entry into a permit-required confined space requires that each member of the entry team is properly trained and authorized to safely enter and perform the work. The entry team is composed of the entrant, the attendant, and the entry supervisor.

OSHA requires that your employer provide any necessary equipment at no cost to you to ensure your safe entry and exit of the permit space. Equipment includes ventilation, testing and monitoring instruments to maintain an acceptable atmosphere quality. Equipment may also include communication devices to monitor your status and provide evacuation alerts, any personal protective equipment necessary for adequate protection, and appropriate lighting to enter, work, and exit safely. Your employer must also provide barriers or shields to protect you from external hazards, such as electrical hazards or sources of extreme heat and cold, and ladders or other equipment for safe entrance and exit.

Your employer must have a rescue plan and trained rescue personnel in place before any employees may enter a permit-required confined space.